One of Medium's first collections features photos both beautiful and odd.

Obvious, the company led by Twitter co-founders Evan Williams and Biz Stone, has been busy building a collaborative publishing tool called Medium, and today it previewed what it has been working on.

With the launch of the new platform, the company is "re-imagining publishing in an attempt to make an evolutionary leap," Williams explained today in a company blog post.

"Lots of services have successfully lowered the bar for sharing information, but there's been less progress toward raising the quality of what's produced," Williams wrote. "While it's great that you can be a one-person media company, it'd be even better if there were more ways you could work with others."

That's the goal of Medium, which takes submitted content such as text and photos and organizes related items in collections that multiple people can review and add to. Instead of being listed chronologically, posts getting the highest user rating will appear at the top, Williams said in the post:

Medium is designed to allow people to choose the level of contribution they prefer. We know that most people, most of the time, will simply read and view content, which is fine. If they choose, they can click to indicate whether they think something is good, giving feedback to the creator and increasing the likelihood others will see it.

Posting on Medium (not yet open to everyone) is elegant and easy, and you can do so without the burden of becoming a blogger or worrying about developing an audience. All posts are organized into "collections," which are defined by a theme and a template. (For example, this post is in the About Medium collection with a simple article template.)

Only a limited number of people will be able to post at the beginning, but here are some of the collections created for preview purposes:

Been There. Loved That. -- A collection of photos, usually beautiful but also mixing in the artistic and just plain odd.